designed to be of welded steel construction. This had to be regarded as a new construction, which is why car body loading tests were carried out with appropriate measurements. The matching unpowered cars, by contrast, have fully welded lightweight car bodies. The entire train composition from was designed the beginning to be operated by one man. Therefore, all doors are equipped with a pneumatic door locking feature that can be operated from the cab (side selective door release). The doors have push button pre-selection keys adjacent to them. They also have a door closure system that closes the doors automatically when the vehicle starts moving, and keeps them closed while driving. In the interior, attention was given to ensuring that enough hand rails were available for the standing passengers expected in normal service. The bogies are fitted with side steerers and are unpivoted. All axles are equipped with disc brakes. The traction motors are horizontally opposed, and outfitted with custom gears. This arrangement — although expensive — has advantages in minimising vibration of the bogie. The vehicle has two two-axle bogies, with individually driven axles, and is therefore classified as Bo′Bo′. The built-in multiple unit train control is designed to operate up to three units. To ensure a quick connection and disconnection, the vehicles are fitted with a +GF+ brand device, which, in addition to the mechanical connectors, simultaneously couples the electrical and pneumatic lines. The vehicles can accelerate at a rate of . Their permissible maximum speed is . The electric brake can slow the vehicles at a similar rate of 0.8 m/s², down to . At that point, the vehicle switches automatically to the electropneumatic brake, to compensate for the declining electric braking performance. The electric brake is also designed for continuous loading, which occurs in applications such as persistent braking of a fully loaded train on a 4.5 ‰ slope (e.g. Davos – Küblis). The vehicles' output per hour is at . Operation The Be 4/4 themselves have seating for 40 second class passengers. Whole trains, including an intermediate car (B) and a driving car (ABt), have a total of 12 first class seats, 136 second class seats, and also 22 fold down seats. The main application served by these Vorortspendel trains was and is regional traffic in the environs of Chur. Operations on the Davos – Filisur line and in the Engadin have been for only